There is an ongoing outage on the primary CPAN mirror. It is possible to work around the issue by using MetaCPAN as a mirror.

INGY / YAML-Diff-0.0.2 / Changes 
0.0.2 Sat Oct 11 19:05:34 CEST 2014
 - Add Mo dependency.

0.0.1 Mon Sep 15 09:27:16 PDT 2014
 - First release